MLL-MLLT10 fusion in acute monoblastic leukemia: variant complex rearrangements and 11q proximal breakpoint heterogeneity

Cytogenetic studies of acute monoblastic leukemia cases presenting MLL-MLLT10 (alias MLL-AF10) fusion show a broad heterogeneity of chromosomal breakpoints. We present two new pediatric cases (French-American-British type M5) with MLL-MLLT10 fusion, which we studied with fluorescence in situ hybridization. In both we detected a paracentric inversion of the 11q region that translocated onto chromosome 10p12; one case displayed a variant complex pattern. We review the cytogenetic molecular data concerning the proximal inversion breakpoint of 11q and confirm its heterogeneity.     

PCR assay for the detection and the identification of atypical canine coronavirus in dogs

Comparative sequence analysis of the PCR products of the M gene and fragments of the pol1a and pol1b genes of canine coronavirus (CCoV) have demonstrated that two separate clusters of CCoV are present in dogs. This note describes a PCR assay to identify atypical CCoV strains with nucleotide substitutions in the M gene. A total of 177 faecal samples from dogs CCoV positive previously with the PCR assay were analysed. Sixty-two of the 177 samples were amplified with the PCR described in the present study and were thus considered atypical CCoVs. The specificity of the PCR typing assay was confirmed by sequence analysis of the PCR products.     

Sodium hypochlorite-, chlorine dioxide- and peracetic acid-induced genotoxicity detected by the Comet assay and Saccharomyces cerevisiae D7 tests

Mutagenicity of drinking water is due not only to industrial,agricultural and urban pollution but also to chlorine disinfectionby-products. Furthermore, residual disinfection is used to providea partial safeguard against low level contamination and bacterialre-growth within the distribution system. The aims of this studywere to further evaluate the genotoxic potential of the worldwide used disinfectants sodium hypochlorite and chlorine dioxidein human leukocytes by the Comet assay and in Saccharomycescerevisiae strain D7 (mitotic gene conversion, point mutationand mitochondrial DNA mutability, with and without endogenousmetabolic activation) and to compare their effects with thoseof peracetic acid, proposed as an alternative disinfectant.All three disinfectants are weakly genotoxic in human leukocytes(lowest effective dose 0.2 p.p.m. for chlorine dioxide, 0.5p.p.m. for sodium hypochlorite and peracetic acid). The resultsin S.cerevisiae show a genotoxic response on the end-pointsconsidered with an effect only at doses higher (5- to 10-fold)than the concentration normally used for water disinfection;sodium hypochlorite and peracetic acid are able to induce genotoxiceffects without endogenous metabolic activation (in stationaryphase cells) whereas chlorine dioxide is effective in growingcells. The Comet assay was more sensitive than the yeast tests,with effective doses in the range normally used for water disinfectionprocesses. The biological effectiveness of the three disinfectantson S.cerevisiae proved to be strictly dependent on cell-specificphysiological/biochemical conditions. All the compounds appearto act on the DNA and peracetic acid shows effectiveness similarto sodium hypochlorite and chlorine dioxide. ¹Author to whom correspondence should be addressed. Tel: +39 0521 905608; Fax: +39 0521 905604; Email: mutgen{at}unipr.it Received on September 22, 2003; revised and accepted on November 27, 2003     

Farnesoid X receptor activation improves erectile function in animal models of metabolic syndrome and diabetes

IntroductionThe farnesoid X receptor (FXR) is critically involved in the regulation of the hepato‐biliary system. Recent data suggest a role for FXR in modulating other metabolic pathways and vascular function.AimTo investigate whether long‐term administration of the selective FXR agonist INT‐747 ameliorates erectile function, we tested it in two animal models of metabolic derangements: a rabbit model of high‐fat diet (HFD)‐induced metabolic syndrome (MetS) and a rat model of streptozotocin (STZ)‐induced type 1 diabetes.MethodsHFD rabbit or STZ rats with or without chronic INT‐747 dosing (10 mg/kg/day for 12 weeks). INT‐747 addition to rabbit penile smooth muscle cells (rpSMCs).Main Outcome MeasureEffects of INT‐747 on metabolic features and erectile function in animal models and clarification of mechanism of action in isolated cells.ResultsINT‐747 dosing normalized visceral adiposity and glucose intolerance in HFD rabbits. INT‐747 increased penile FXR expression and partially restored endothelial nitric oxide synthase and dimethylarginine dimethylaminohydrolase 1 expression as well as impaired nitric oxide (NO)‐dependent relaxation (improved responsiveness to acetylcholine and electrical field stimulation). INT‐747 was also effective in regulating NO downstream events, as shown by increased sodium nitroprusside‐induced relaxation. Because phosphodiesterase type 5 and protein kinase G (PKG) were unaltered by INT‐747, we analyzed the calcium‐sensitizing RhoA/ROCK pathway. HFD increased, and INT‐747 normalized, RhoA membrane translocation/activation. RhoA/ROCK signaling inhibition by INT‐747 was confirmed in rpSMCs by confocal microscopy, MYPT1‐phosphorylation, cytoskeleton remodeling, cell migration, and smooth muscle‐related genes expression. In STZ rats, FXR penile expression was not altered but was significantly upregulated by INT‐747 dosing. In this model, INT‐747 improved penile erection induced by electrical stimulation of cavernous nerve and hypersensitivity to intracavernous injection of a ROCK‐inhibitor, Y‐27632, without improving hyperglycemia.ConclusionIn HFD rabbits, INT‐747 dosing improved glucose sensitivity and MetS‐associated erectile dysfunction, via upregulation of NO transmission and inhibition of RhoA/ROCK pathway. In STZ rats, INT‐747 restored in vivo penile erection and sensitivity to ROCK inhibition, independently of effects on glycemia. Vignozzi L, Morelli A, Filippi S, Comeglio P, Chavalmane AK, Marchetta M, Toce M, Yehiely‐Cohen R, Vannelli GB, Adorini L, and Maggi M. Farnesoid X receptor activation improves erectile function in animal models of metabolic syndrome and diabetes.     

Pentraxin‐3 is upregulated in the central nervous system during MS and EAE,but does not modulate experimental neurological disease

Pentraxin‐3 (PTX3), an acute‐phase protein released during inflammation, aids phagocytic clearance of pathogens and apoptotic cells, and plays diverse immunoregulatory roles in tissue injury. In neuroinflammatory diseases, like MS, resident microglia could become activated by endogenous agonists for Toll like receptors (TLRs). Previously we showed a strong TLR2‐mediated induction of PTX3 in cultured human microglia and macrophages by HspB5, which accumulates in glia during MS. Given the anti‐inflammatory effects of HspB5, we examined the contribution of PTX3 to these effects in MS and its animal model EAE. Our data indicate that TLR engagement effectively induces PTX3 expression in human microglia, and that such expression is readily detectable in MS lesions. Enhanced PTX3 expression is prominently expressed in microglia in preactive MS lesions, and in microglia/macrophages engaged in myelin phagocytosis in actively demyelinating lesions. Yet, we did not detect PTX3 in cerebrospinal fluid of MS patients. PTX3 expression is also elevated in spinal cords during chronic relapsing EAE in Biozzi ABH mice, but the EAE severity and time course in PTX3‐deficient mice did not differ from WT mice. Moreover, systemic PTX3 administration did not alter the disease onset or severity. Our findings reveal local functions of PTX3 during neuroinflammation in facilitating myelin phagocytosis, but do not point to a role for PTX3 in controlling the development of autoimmune neuroinflammation.     

Effectiveness of combined GnRH analogue plus raloxifene administration in the treatment of uterine leiomyomas: a prospective,randomized, single-blind,placebo-controlled clinical trial

BACKGROUND: Raloxifene hydrochloride is a synthetic non-steroidal drug used for the prevention and treatment of post-menopausal osteoporosis. Pre-clinical and clinical data have shown that raloxifene may have a beneficial effect on leiomyomas. The aim of this prospective single-blind, randomized, placebo-controlled clinical trial was to evaluate the effectiveness of the addition of raloxifene to GnRH analogues on uterine, leiomyoma, and non-leiomyoma sizes, and on the occurrence of leiomyoma-related symptoms. METHODS: After randomization using a computer-generated list, 100 pre-menopausal women with symptomatic uterine leiomyomas received either leuprolide acetate depot plus raloxifene 60 mg daily (group A) or leuprolide plus placebo tablet (group B) for six cycles of 28 days. At baseline and after treatment, uterine, leiomyoma and non-leiomyoma sizes, and leiomyoma-related symptoms were evaluated for each woman. Analysis was by intention-to-treat method. RESULTS: After six cycles of treatment, a significant decrease in uterine, leiomyoma, and non-leiomyoma sizes was detected in both groups in comparison with baseline. At the same time, no significant difference in uterine and non-leiomyoma sizes was observed between the groups. Leiomyoma sizes were significantly (P < 0.05) lower in group A than in group B. No difference was observed in leiomyoma-related symptoms between groups throughout the study period. CONCLUSIONS: In women treated with GnRH analogue, the raloxifene administration induces a higher reduction of leiomyoma sizes.     

Nitrergic Neurons in the Spinal Cord of the Bottlenose Dolphin (Tursiops truncatus)

Nitric oxide (NO) is a freely diffusible gaseous neurotransmitter generated by a selected population of neurons and acts as a paracrine molecule in the nervous system. NO is synthesized from l ‐arginine by means of the neuronal nitric oxide synthase (nNOS), an enzyme requiring nicotine adenine dinucleotide phosphate (NADPH) as cofactor. In this study, we used histochemical and immunohistochemical techniques to investigate the distribution of NADPH‐diaphorase (NADPH‐d) and nNOS in the spinal cord of the bottlenose dolphin (Tursiops truncatus). Cells with a fusiform‐shaped somata were numerous in the laminae I and II. The intermediolateral horn showed darkly‐stained cells with a multipolar morphology. Neurons with a multipolar or fusiform morphology were observed in the ventral horn. Multipolar and fusiform neurons were the most common cell types in lamina X. Nitrergic fibers were numerous especially in the dorsal and intermediolateral horns. The presence of nitrergic cells and fibers in different laminae of the spinal cord suggests that NO may be involved in spinal sensory and visceral circuitries, and potentially contribute to the regulation of the complex retia mirabilia. Anat Rec, 296:1603–1614, 2013. © 2013 Wiley Periodicals, Inc.     

Loss of miR‐101 expression promotes Wnt/β‐catenin signalling pathway activation and malignancy in colon cancer cells

Colorectal cancer (CRC) is the second leading cause of cancer‐related mortality in Western countries. Although the aberrant expression of several microRNAs (oncomiRs) is associated with CRC progression, the molecular mechanisms of this phenomenon are still under investigation. Here we show that miR‐101 expression is differentially impaired in CRC specimens, depending on tumour grade. miR‐101 re‐expression suppresses cell growth in 3D, hypoxic survival and invasive potential in CRC cells showing low levels of miR‐101. Additionally, we provide molecular evidence of a bidirectional regulatory mechanism between miR‐101 expression and important CRC pro‐malignant features, such as inflammation, activation of the Wnt/β‐catenin signalling pathway and epithelial–mesenchymal transition (EMT). We then propose that up‐regulated miR‐101 may function as a tumour suppressor in CRC and that its pharmacological restoration might hamper the aggressive behaviour of CRC in vivo. MiR‐101 expression may also represent a cancer biomarker for CRC diagnosis and prognosis. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.